GPU-Acoustics

This project demonstrates a prototype me (John Daniel Bossér) and my father (Lennart Bertil Bossér) made for the International Conference on Underwater Acoustics (ICUA). A paper about this project can be found here.

Some addititional implementation notes can be found in the latex folder.

Running the project

Dependiencies

To run the project, you need a modern web-browser with support for WebGL. The project has only been tested in recent versions of firefox, but other modern browsers should in theory be supported.

Other dependencies include python3 to start a server that hosts the application and to plot the produced results.

Cloning the project

To get a local copy of the project, you must run

git clone --recurse-submodules https://github.com/jdbosser/GPU-Acoustics.git

to ensure that you get all the needed submodules. This can take a while, since three.js (interface to WebGL) is rather large.

Create a python virtual environment and run the project

It is a common practice to create an isolated python environment to install the requirements. To install everything python-related needed to run the project, do the following:

Create a python environment named env:

python3 -m venv env

On linux/macOS with bash:

source env/bin/activate

On windows:

.\env\Scripts\activate

To install the requirements to run the project

pip install -r requirements.txt

You should now be able to run the project:

python3 -m http.server

and open the project in a web browser. If you have firefox, you can run:

firefox localhost:8000

To leave the virtual environment when you are done with your experiments, run

deactivate

Usage

The application shows two different views.

• Left: Control view. Here, you can view your uploaded module, zoom in and out, and rotate. Note that you are actually not rotating the model in relation to the incoming acoustic signal. You are only viewing the geometry from a different angle.
• Right: Computation view. This image is the actual image used to compute the target strength, see equation (2) in the conference paper.

To get a different incoming angle towards the model, you need to rotate the model itself. This can be done from the control panel in the top right corner.

Control panel

The control panel also allows you to change

• Wavelength
• Phaseshift
• Turn of automatic calculation of TS (speeds up the program)
• Turn on visibility of the GPU-camera, which creates the image used to calculate the TS.
• Model rotation and material. Note that you need to use the complex material in order to get correct TS values.

You can also trigger routines from the control panel:

• "r = 2m" sphere test calculates the target strength of a sphere with a radius of 2 meters for different wavelengths. This routine creates the data presented in figure 2 in the conference paper.
• "TS for every degree": Calculates the target strength for every whole angle between 0 and 360.
• "TS for every wavelength": Calculates the TS for all wavelengths between 10 Hz and 100000 Hz.

The routines create .json files that the user is prompted to download. These files contains TS and either the corresponding wavelength or angle.

Plotting the results

Example files to parse and plot the results are provided in the results folder.

After running one of routines, you will be prompted to download a file. You can place this file with the name <filename>.json in the results folder and then plot it by running

python logplot.py <filename>.json 

python polarplot.py <filename>.json 

python sweeplot.py <filename>.json 

Some premade calculations exist in the results/precalculated-folder. These can be plotted by running

python plot_precalculated.py

Change model

You can change the model by clicking "Upload 3D-model" in the top left corner. Only .stl files are supported currently.

Bugs

Sometimes, the model wont show up in the left panel. This can be fixed by refreshing the page a couple of times. Why this happens stochastically, I have no idea ¯_(ツ)_/¯

Citation

If you want to use the results from this project, or make a continuation of it, please cite it by using the following BibTex:

@article{doi:10.1121/2.0001301,
author = {Bossér,Lennart Bertil  and Bossér,John Daniel },
title = {Target Strength Calculation using the Graphics Pipeline},
journal = {Proceedings of Meetings on Acoustics},
volume = {40},
number = {1},
pages = {070004},
year = {2020},
doi = {10.1121/2.0001301},

URL = { 
        https://asa.scitation.org/doi/abs/10.1121/2.0001301
    
},
eprint = { 
        https://asa.scitation.org/doi/pdf/10.1121/2.0001301
    
}

}